Apparatus for making divergent cuts chamfered relative to a cutting surface by means of torch cutting

ABSTRACT

The invention relates to an apparatus for making divergent cuts chamfered relative to a cutting surface, e.g. welding chamfers, by means of torch cutting particularly in the internal cutting of cylindrical sheets, such as pipes. The apparatus comprises a torch (8) mounted on a fastening arm (2) at the end of a carrier arm (1), said carrier arm (1) being axially movable and rotatable around its axis. The fastening arm (2) at the end of carrier arm (1) is fitted with a transverse support arc (3), which carries an element (4) movable along an arcuate path and fitted with a longitudinal support arc (5), the latter carrying a mounting plate (6) for torch (8), the plate being movable along an arcuate path. The radii of the arcuate paths of support arcs (3, 5) are equal and their centers are equally far from the center line of carrier arm (1) at an axial distance from each other.

The present invention relates to an apparatus for making divergent cutschamfered relative to a cutting surface, e.g. welding chamfers, by meansof torch cutting, especially in the internal cutting of cylindricalsheets, such as pipes.

In industrial manufacturing, the cutting of pieces, the removal ofpieces from a sheet, the cutting off of profiled irons and pipes andlike require not only the cutting but also a chamfer for welding. Thereare several different means and devices for producing chamfers in freespace but those cannot be applied to the internal cutting of rathersmall pipes by using a cutting torch guide disclosed in Patentapplication W086/04003. According to its operating principle, this priorart cutting torch guide carries a torch along the internal wall of acylindrical jacket at a set working distance from the wall.

An object of the invention is to provide an apparatus for varying theinclination of the cutting direction of the burner head of a cuttingtorch while the path of the tip portion of said burner head follows adesired cutting line.

This object is achieved by means an apparatus of for making divergentcuts chamfered relative to a cutting surface by means of torch cuttingin the internal cutting of cylindrical sheets. The apparatus includes atorch mounted on a fastening arm at the end of a carrier arm, thecarrier arm being adapted to be axially movable and rotatable around itsaxis. The fastening arm at the end of the carrier arm is fitted with atransverse support arc provided with an element movable along an arcuatepath and fitted with a longitudinal support arc which is provided with amounting plate for the torch. The mounting plate is movable along anarcuate path whereby the radii of the arcuate paths of the support arcsare equal and their centers are equally far from the center line of thecarrier arm at an axial distance from each other.

The invention will now be described in more detail with reference madeto the accompanying drawings, in which

FIG. 1 shows an apparatus of the invention in a schematic perspectiveview,

FIG. 2 shows a structural component of the apparatus of FIG. 1 as seenfrom the front,

FIG. 3 is a section of the structural component of FIG. 2 along a line3--3,

FIG. 4 is a section of the structural component of FIG. 2 along a line4-4,

FIG. 5 illustrates an application of the invention to the cutting of acylindrical surface, and

FIG. 6 shows a section through FIG. 5 along a line 6--6.

As shown in FIG. 1, the apparatus of the invention comprises a block 15secured to a fastening arm 2 at that end of a carrier arm 1 which iscloser to a torch 8, said block 15 being fitted with a transversesupport arc 3 provided with an element 4 traveling along an arcuatepath. To said moving element 4 is secured a block 16 fitted with alongitudinal support arc 5 provided with a mounting plate 6 for a torch8, said plate traveling along an arcuate path. The radii of the arcuatepaths of support arcs 3, 5 are equal and their centers are equally farfrom the center line of carrier arm 1 at an axial distance from eachother.

The traveling path of moving element 4 runs preferably in the samedirection as the rim of transverse support arc 3, the plane of saidtraveling path being perpendicular to the center line of the carrierarm. On the other hand, the traveling path of moving mounting plate 6runs preferably in the same direction as the rim of longitudinal supportarc 5, the plane of this traveling path being parallel to the verticalplane of carrier arm 1.

The moving element 4 and the moving mounting plate 6 each has its ownshifting mechanism, whereby said moving elements 4, 6 can beindependently adjusted. The shifting mechanisms are both identical,comprising a driving cable 9, a driving cable inlet 14, driving cablereversing wheels 10, a driving cable fastening means 11 for securing thedriving cable to moving element 4, 6, as well as guide tracks 12 withtheir guide wheels 13 (FIGS. 2-4).

In one preferred embodiment of an apparatus of the invention, a drivemeans (not shown) for driving cable 9 is mounted on the end of carrierarm 1 away from the torch, so that said driving cable 9 extends inside ahollow carrier arm 1.

The moving element 4, 6 is preferably mounted with three guide wheels 13so as to be movable between V-tracks 12. When driving cable 9 is drivenin a desired direction by means of said drive means, said moving element4, 6 swings accordingly through the intermediary of locking means 11. Bycombining the movements of moving elements 4, 6, the traveling path oftorch 8 can be as desired.

The support arcs 3 and 5 are normally positioned in a manner that saidtorch 8 is perpendicular to the surface to be cut. In cutting acylindrical surface, as shown in FIG. 5, so that the carrier arm 1 of acutting torch guide disclosed in the above-cited Patent applicationW086/04003 turns through an angle α, said cutting torch 8 remains allthe time perpendicular to the wall of a cylinder M. A position differentfrom the perpendicular position, as e.g. line k₂ or l₂, is obtained byturning said moving element 4 by means of the shifting mechanism in adesired direction, whereby the support arc 5 secured thereto turnsaccordingly and causes said torch 8 to turn relative to a perpendicularline j₂ while the intersection 7 remains the same.

In the section, 6--6 of FIG. 6, there is shown the position of torch 8in the plane of the longitudinal axis of a carrier arm. A desiredchamfer angle, e.g. along lines kl or ml, is obtained by turning saidmoving mounting plate 6 by means of the shifting mechanism to a desiredposition, whereby said torch 8 turns in the plane of the longitudinalaxis of carrier arm 1 around intersection 7.

The above-described embodiments are not intended to limit but only toclarify an inventive idea set forth in the annexed claims.

I claim:
 1. An apparatus for making divergent cuts chamfered relative toa cutting surface by means of torch cutting in the internal cutting ofcylindrical sheets, said apparatus comprising a torch (8) mounted on afastening arm (2) at the end of a carrier arm (1), said carrier arm (1)being adapted to be axially movable and rotatable around it axis,wherein the fastening arm (2) at the end of the carrier arm (1) isfitted with a transverse support arc (3) provided with an element (4)movable along an arcuate path and fitted with a longitudinal support arc(5), the latter being provided with a mounting plate (6) for torch (8),said mounting plate being movable along an arcuate path, whereby theradii of the arcuate paths of support arcs (3, 5) are equal and theircenters are equally distance from each other.
 2. An apparatus as setforth in claim 1, wherein the traveling path of moving element (4) runsin the same direction as the rim of transverse support arc (3), theplane of said traveling path being perpendicular to the center line ofcarrier arm (1).
 3. An apparatus as set forth in claim 1, wherein thetraveling path of moving mounting plate (6) runs in the same directionas the rim of longitudinal support arc (5), the plane of said travelingpath being perpendicular to the plane of the traveling path of movingelement (4).
 4. An apparatus as set forth in claim 1, wherein saidmoving element (4) and moving mounting plate (6) are provided withseparate shifting mechanisms, said moving elements (4, 6) beingindependently movable.
 5. An apparatus as set forth in claim 4, whereinthe shifting mechanism for said moving element (4, 6) comprises adriving cable (9), a driving cable inlet (14), driving cable reversingwheels (10), a driving cable fastening means (11) for fastening thedriving cable to moving element (4, 6), as well as guide tracks (12)with their guide wheels (13).
 6. An apparatus as set forth in claim 5,wherein in that the drive means for driving cable (9) is mounted on theend of carrier arm (1) away from the torch, said driving cable (9)running inside a hollow carrier arm (1).